The present invention relates to pharmaceutical compositions and methods for treating or preventing pain, inflammation, and epilepsy.
Pain is a common form of physical suffering and distress and is one of the most common reasons patients report to physicians. It may be categorized in terms of form (nociceptive or neuropathic), duration (chronic or acute), and degree (mild, moderate or severe). Typically, nociceptive pain is acute, and results from injury, such as burns, sprains, fractures, or inflammation (inflammatory pain, including from osteo- and rheumatoid arthritis). Neuropathic pain, on the other hand, is defined by the International Association for the Study of Pain as a form of chronic pain that is caused by a lesion or dysfunction of the nervous system. Commonly, neuropathic pain results from diabetic neuropathy, HIV infections, or post-herpetic neuralgia. Other disorders that are associated with neuropathic pain include complex regional pain syndromes, trigeminal neuralgia, low back pain, sciatica, phantom limb pain, blast pain, fibromyalgia, and other conditions that result in chronic pain. Few therapeutics are approved by the U.S. Food and Drug Administration and other regulatory agencies for the treatment of neuropathic pain. Those that are approved exhibit, at best, a modest efficacy in terms of pain reduction (see Jensen, Eur. J. Pain 2002; 6 Suppl A:61-68).